Actuating mechanism for unlocking the safety-catch of a foldable back of a car seat

ABSTRACT

An actuating mechanism for unlocking the safety-catch of a foldable back, equipped with angle adjusting mechanism, of a car-seat has a control cable attached to the upper actuating lever and reversed forward via a lower reversing position and acting on the safety-catch which acts with a locking pin. Provided between the lower reversing position and the safety-catch, below the control cable, is an additional reversing mechanism which moves the lower control cable area upward in relation to its stretched state and, in the state of utilization of the seat-back, always maintains equal the angle of wrap of the typically provided lower reversing position in all leaning positions. This results in a considerable gain in adjusting path for the actuating lever.

FIELD OF THE INVENTION

The present invention relates to an actuating mechanism for unlockingthe safety-catch of a foldable back, equipped with the angle adjustingmechanism, of a car-seat.

BACKGROUND OF THE INVENTION

With such actuating mechanisms there is the problem that only a limitedswivelling angle is available for the swivelling path of the actuatinglever. This swivelling angle cannot be increased resulting consequencesfor operating quality. In this connection, it proves to be adisadvantage that the available swivelling range, already limited,anyway, which determines the actuating course of the safety-catch,cannot be fully utilized. The ability to utilize the swivelling angle isreduced because the seat back cannot be folded into the forward positionfrom a preset fixed position, but rather the folding procedure must bepossible with every one of the leaning settings conceivable for use. Inactuality, a swivelling path of 40°, as an example, is reduced by 10°,for example, because the seat-back angle adjustable with an angleadjusting mechanism can easily vary by 60° or more in the state of use.

SUMMARY OF THE INVENTION

The present invention is based on the technical problem of designing anactuating mechanism of the known kind in such a way that the adjustingpath of the actuating lever can always be utilized to its full extentfor actuating the safety-catch, independently of the basic angle of theseat-back as set.

The result of providing an additional reversing mechanism between thelower reversing position and the safety-catch is that the angle of wrapof the control cable around the lower reversing position is practicallythe same in each of the positions of use that are determined by theadjusting range of the angle adjusting mechanism, unlike in the knownsolution without additional reversing where the angle of wrap of thelower reversing position does not change depending on the leaningposition set for use. In this way, in the present invention the entireadjusting path created by the actuating lever is available for unlockingthe safety-catch.

BRIEF DESCRIPTION OF THE DRAWINGS

The preferred embodiment of the invention is illustrated in theaccompanying drawings, wherein:

FIG. 1 shows a schematic side view of a seat-back with an adapter in anextremely far forward position,

FIG. 2 shows the illustration according to FIG. 1 in utilizationposition of the seat-back, and

FIG. 3 shows the illustration according to FIGS. 1 and 2 with theseat-back leaned as far back as possible.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Seatback 2 supports, at its upper end, an actuating lever 4 designed asa one-armed lever pivotally supported about a bearing support 5 at theupper end of the seat-back. Attached to the actuating lever 4 is acontrol cable 3 which, approximately in the area of the middle of theseat-back, is guided forwardly in relation to its stretched state by aguide element 8, for example a roller. The control cable 3 runs througha lower circular or cylindrical reversing position member 6 whose centerline is designated as number 7. The center line 7 coincides, at leastapproximately, with the swivelling axis of the angle Adjusting mechanismor the swivelling axis around which the seat-back is pivotally attachedto adapter 11. Between the adapter 11 and the seat-back 2, in the areaof the swivelling axis 7, and with at least approximately the same axis,is the angle adjusting mechanism (not shown) which, for example, can bea known, wide wobble gear. With this angle adjusting mechanism, thebasic angle of the seat-back 2 in relation to the adapter 11 is set.

The adapter 11 is, in turn, hinged around a bolt 12 that connects theadapter in a swivelling manner with the seat. The center of the bolt 12forms the swivelling axis around which the adapter can be swivelledtogether with the seat-back 2, when the safety-catch 1 is released. Thesafety-catch 1 is lodged swivelling around a bolt 15 and, in lockedstate, grasps from behind a locking pin 10 which is also fixed on theseat (not shown). A restoring spring 13 always pulls the safety-catch 1into the locking position shown in FIG. 1. For unlocking thesafety-catch 1, the actuating lever 4 is pulled out of a basic position(solid) via the middle position (broken-line), into the upper endposition (broken-line), in the direction of the arrow 14. In the upperposition, marked in broken-line, the safety-catch 1 has released thelocking pin 10 and the seat-back 2 can be swung forward around the bolt12 by means of the adapter 11.

The leaning position shown in FIG. 1 is an extremely far forward leaningposition, which can be adjusted for the transport of bulky objectsbehind the passenger seat. Only in this extremely far forward leaningposition shown in FIG. 1, situated outside the actual range of use, isthe control cable 3 stretched in the area between the lower reversingposition 6 and the safety-catch 1. In this position, the additionallower reversing mechanism 9 only rests precisely against the stretchedcontrol cable area.

In all other actual leaning states of the seat-back, corresponding topractical cases of use, the lower reversing mechanism 9, designed as areversing roller, always presses the horizontal control cable areaupwardly with the result that it enlarges the angle of wrap a₃ in FIG. 3and a₂ in FIG. 2 in relation to what it would have been without theadditional reversing mechanism 9.

Only in the extreme position shown in FIG. 1, which marks the limit ofthe range of use, does the lower reversing mechanism 9 no longer affectthe then stretched course of the horizontal control cable portion. Theangle of wrap al in this extreme position is equal to the angles of wrapa₂ and a₃. This feature of the invention ensures that cable 3 remainstaut in each of the angular positions of the seat-back 2 in relation tothe seat bottom. This ensures that rotation of lever 4 between its twoextreme positions results in rotation of safety catch 1 so as to permitrotation of seat back 2.

What is claimed is:
 1. An apparatus for unlocking a safety-catch of carseat with a foldable seat back, said apparatus comprising:an actuatinglever swingably mounted on a bearing member at a, lateral upper end ofsaid seat back; an adapter pivotally attached to a lower lateral end ofsaid seat back and adapted to interconnect the seat back with a seatbottom; a control cable having one end attached to said actuating lever,an intermediate portion resting on a lower reversing element, and itssecond end attached to a safety catch, said cable following an adjustingpath which varies with the angle of said seat back; said lower reversingelement having a shape at least partially circular forming part of thepath of said cable from said actuating lever to said safety catch, saidlower reversing element having a center line which substantiallycoincides with a swiveling axis of said seat back; and an additionalreversing element fixed to said seat back between said lower reversingelement and said safety catch, said additional reversing element movingthrough an angle about said swivel axis equal through which the seatback moves, said additional reversing element wraps said cable betweensaid lower reversing element and said catch on said lower reversingelement as said cable between said actuating lever and said lowerreversing element is unwrapped by the seat back being moved and saidadditional reversing element unwraps said cable when said seat backwraps said cable to maintain the angle of wrap of said control cablearound said lower reversing element such that the angle of wrap issubstantially constant when of the angle of the seat back varies.
 2. Theapparatus according to claim 1, wherein the additional reversing elementis a reversing roller.
 3. The apparatus according to claim 1 wherein thelower reversing element is a transfer tube running between oppositelower lateral sides of the seat-back.
 4. The apparatus according toclaim 2 wherein the lower reversing element is a transfer tube runningbetween opposite lower lateral sides of the seat-back.
 5. The apparatusaccording to claim 1 wherein said additional reversing element isadapted to press said control cable upward to enlarge said angle of wrapwith respect to what it would have been without said additionalreversing element.
 6. The apparatus according to claim 1 wherein saidadditional reversing element enlarges said angle of wrap only within apredetermined range of use of said seat back.